Something has found its way into the Prison -- or at least that's what the new promo for "The Walking Dead" Season 4 leads us to believe. Just like the recently-debuted poster promises, a new short trailer for the upcoming season shows that the Prison isn't as safe as it once (sort of) was.

Another similarly short teaser reveals quick cuts of our favorite survivors as someone begs them, "Please help me." Moral choices of who to welcome into Rick & Co.'s group and who they should exclude have been explored on "The Walking Dead" in the past, most notable in Season 3's "Clear," and it looks like it's a subject that will remain relevant going into Season 4.

"The Walking Dead" returns to AMC on Oct. 13 at 9 p.m. ET. Season 4 will introduce some new characters, like Lawrence Gilliard Jr.'s Bob Stookey. It will also see some of the Woodbury survivors come to the forefront now that they've been incorporated into the Prison group.